EConomic grows is my answer im not sure if its right tho
I believe the answer is oxygen only
answer:
by having a high genetic level of melanin in your skin, you're skin is more protected from the ultra violet sun rays. Darker skinned races have more melanin present, these races originate from hot countries where sunlight is often present; the production of melanin in their skin allows them to reflect and inhibits they're skin from becoming extremely damaged. Light skinned races don't have a large amount of melanin due to they're native countries lacking sunlight. This is an evolutionary adaptation of the human race.